This invention relates generally to speech simulation systems and methods, and more particularly to a system and method for presenting simulated speech in a sensory perceptible form to substitute for or to augment hearing.
Various devices and methods are known for assisting hearing-handicapped individuals to receive speech. Sound amplifying devices, such as hearing aids, may be capable of affording a satisfactory degree of hearing to some with a hearing impairment. Devices capable of presenting speech in a visual or tactile form have also been proposed. However, these devices typically present speech on the basis of its frequency content, and, in general, they are more useful for mimicking speech (as for speech therapy purposes) than for interpreting speech. Consequently, they are not very useful for assisting hearing-handicapped persons to communicate naturally in a hearing environment.
For the deaf or those with severe hearing impairments no means is available that enables them to receive conveniently and accurately speech with the speaker absent from view. With the speaker in view, a deaf person can speech read, i.e., lip read, what is being said, but often without a high degree of accuracy. Also, the speaker's lips must remain in full view to avoid loss of meaning. Improved accuracy can be provided by having the speaker "cue" his speech using Cued Speech hand forms and hand positions to convey the phonetic sounds in the message. The hand forms and hand positions convey approximately 40% of the message and the lips convey the remaining 60%. An AutoCuer, under development by R. Orin Cornett, the originator of Cued Speech, can present the hand form and hand position cues for the speaker, but to use the device the speaker's face must still be in view.
The speaker may also convert the message into a form of sign language understood by the deaf person. This can present the message with the intended meaning, but not with the choice of words or expression of the speaker. The message can also be presented by fingerspelling, i.e., "signing" the message letter-by-letter as in Braille, or, of course, the message can be written out and presented.
Such methods of presenting speech require the visual attention of the hearing-handicapped person which, in the long run, can visually handicap the person because his or her visual habits become trained to favor communication rather than observation. Moreover, speech presentation methods such as Cued Speech, sign language and finger-spelling are not practical in an everyday hearing environment since they require specially trained speakers.